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Cracking Candy Finish

#1
I made up samples with the Paint With Pearl candy concentrate powder in the SPI Intercoat I mixed up with SPI reducer 1-1 and sprayed it over a Urekem Silver basecoat, and when I barely bend the spayout cards just a fraction of an inch the next day the resulting finish cracks all over. I'm really concerned about this being a very durable system because usually you can bend materials painted with urethane products all you want and they usually don't crack. I didn't activate the base or the intercoat candy since this was just a sprayout if that makes a difference. I know I need to do a sprayout sample of just the base to see if this is the weak link, but I thought I'd get peoples' words of wisdom on this here to figure out what is wrong in the meantime.

The Urekem base (mixed 1-1) sprayed out really well, and I got the candy coat to look really nice, but I'm worried about the fact that something isn't allowing the finish to have any give to it, which I think I'm going to need if it's going over something like steel that expands and contracts so much with temperature changes.

Thanks for any input on this issue.
 

Barry

Paint Fanatic
Staff member
#2
Sounds right to me, first the base you're using last I knew said can't activate, that tells me it is not a urethane as no polyol to create an OH factor and will be brittle.
Second is it worry other than long-term fastness on a car probably not as if metal bends in inch you will be repairing anyway.
Personally, I would recommend you use their intra coat just for compatibility with that system as I don't want to be blamed down the road for problems.
 
#4
The UreKem base coat tech sheets not only recommend mixing their base 2:1, but also to optionally add activator at the rate of 2 oz. per sprayable quart, both for their colors, and for their IC-100 intercoat. High film build applications like tri-coat and candy should always use activated base, imo, and should also use the same brand of reducer throughout, with extra dry time between materials from different systems.

High film builds of base coat will always tend to be brittle without activator.
 
#5
I was wondering if not activating the products wasn't the problem. I was going to activate everything on the real job - I just didn't want to open a new can of activator just to spray samples with.

Which basecoats have people successfully used the SPI Intercoat Clear over? Is the SPI Intercoat Clear less kind to basecoats than the regular topcoat SPI clears (i.e. more likely to have an adverse reaction with)?
 
#6
i think the intercoat has been used over just about everything by now. never heard of urekem though. the intercoat clear is basecoat and all bases are more harsh and stronger than a urethane clear would be. the spi intercoat is a much harder base than most. the problem with most clear base binders i have used in the past is that they were very soft and gummy which made for real issues when the finish got hot in the sun. i helped barry with testing that stuff many years ago to make it so it had some strength and wasnt like the others. now, question is, what did you do the sprayout on? if you did it on a paper spray out card then the intercoat will crack because the paper swells then shrinks from the solvents. you really need to activate the intercoat. on a regular metal panel, assuming you dont have massive buildup of the intercoat, it will not crack once clearcoat is put on it. only time i have seen this happen is when you put something like 10 heavy under reduced coats with no activtor on so the build is thick then you leave the panel to sit without clear on it for 3-7 days. if the urekem is cracking then you have other issues either with that product, the undercoats are moving or you did your test on a paper card.
 
#7
The paper sprayout cards are what I used for these sprayouts because I normally shoot single stage paint on restoration jobs I do and these cards seem to work well for that type of paint. Looks like they're not so good for three stage paint jobs.

Yes, I know I need to activate the base and mid coat, and I was planning on doing that eventually. I'm mainly trying to figure out the color for now. When I find one that I like and figure out how to mix/spray it then I'll do a sample with everything like I'm going to do on the final job. I just didn't want to waste a bunch of activator if I didn't need to just to determine color.
 
#8
you need to find another base. using that stuff is like buying a new vette and putting continental tires on it .
 
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#9
you need to find another base. using that stuff is like buying a new vette and putting continental tires on it .
What would you recommend? I know in the past when I've asked Barry he has recommended brands like Pro-spray, Matrix and Lesonal. Also I've read on another forum the Wanda - another Akso Nobel brand - is pretty good. If I drive a ways I can get most brands, but it's a real hassle to have to drive 60 miles just to get paint. That's why I ordered the Urekem base because it's easy to buy online.
 
#11
wanda is great, inexpensive and basically the same as lesonal with out the warranty and tech support from akzo. wanda is 90% of what i use. all the others you listed are great as well but i havent used matrix in prob 17 years. mid to upper ppg and basf lines are good as well but your gonna pay. never liked the watery dupont/axalta.
 
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